ExtrudeBufferGeometry causing rotation of output

I am trying to extrude some shapes along custom spline paths, however I am finding that after extruding, the output is looking like it has been rotated a bit.

Reduced it to simpler case of extruding a shape in negative Z direction along a line. If I render the actual shape of the triangle and the extruded shape of the triangle afterwards, extruding works fine but there is a change in orientation of the output and it looks rotated. Any ideas ?

Screenshot 2020-03-28 at 1.05.30 AM



I know this is old, but I found it while searching for the same issue, so I figured I would reply for the next person so looking.
With a little research, I discovered that you cannot in fact control the orientation of the profile being swept. That makes this operation of little use in my opinion, since most real-world cases need to be able to do so.

I am going to first try to modify the source and see if I get a satisfactory result; if so, I will submit it. Otherwise, its roll-my-own time.